This invention relates to slot machines or coin operated gaming machines for playing on random combinations of symbols such as figures, pictures or characters. More specifically the invention pertains to a novel multiline slot machine capable of providing a far greater number of playable symbol combinations per number of symbol display zones heretofore, thereby adding to the fun and amusement of the player.
Poulsen et al. U.S. Pat. No. 4,097,048, dated June 27, 1978, and Andersen U.S. Pat. No. 4,138,114, dated Feb. 6, 1979, both disclose slot machines of typical conventional design. In either case the machine comprises three reels, otherwise called drums, wheels, etc., that are mounted on a common shaft for rotation independently of each other. Each reel bears an annular row of symbols on its peripheral surface. Some symbols on each reel may be alike, but the arrangement of the symbols usually differs from reel to reel. The reels are set into rotation, as by a pull of a handle, and are made to stop in different positions. The player wins the game if a predetermined combination of symbols appears through a window extending across the reels.
A more complex symbol display is offered by a multiline "crisscross" type of machine disclosed, for instance, in Rodesch et al. U.S. Pat. No. 4,099,722 dated July 11, 1978. A typical "crisscross" model simultaneously displays randomly selected symbols in an array of three rows and three columns. Its display screen or window exhibits a total of five pay lines, three horizontal ones and two crossing diagonal ones. Winning and nonwinning combinations of symbols appear along all these pay lines.
For playing on such a multiline slot machine the player must deposit a coin or coins of a required denomination or denominations to choose one, some, or all of the pay lines. He wins if the symbols stop in a prescribed combination or combinations along the line or lines of his choice. The rate of payout (i.e. the ratio of payout to payin) may differ from line to line. In the event of the concurrence of two or more winning combinations along the preselected pay lines the machine will sum up the required amounts and pay the total.
A recent breakthrough in the slot machine art is the use of a cathode ray tube (CRT) for symbol display. As heretofore constructed the "vide slot" machine has simulated the symbol display by the more conventional reel type machines. The CRT screen has displayed vertical rows of symbols as if they were on revolving reels mounted on a common shaft, although, of course, the movement and random stops of the symbol rows are controlled purely electronically. Thus the conventional video slot machine has also been capable of offering only horizontal or diagonal pay lines.
As is apparent from the foregoing study of the prior art, all conventional slot machines have afforded only a pay line or lines extending across the symbol bearing reels, with diagonal lines further yielded by "crisscross" models. No device has so far been suggested which has pay lines in the direction of symbol movement. This only natural because the conventinal belief has been that the rows of symbols to be displayed by the slot machine must be borne by respective reels, either acutal or imaginary, that rotate about one and the same axis. No rule exists, however, that the slot machine must be such.
The contingency or randomness of symbol combinations is the foundation stone of the slot machine. Symbol combinations across the reels, whether horizontal or diagonal, are haphazard since the reels have different symbol arrangements and revolve and stop under different conditions. Prescribed payout rates are allotted to payout lines in such directions depending upon the probability of the occurence of specific symbol combinations. No payout is possible for predetermined symbol combinations. The conventional slot machine constructions inhibit the provision of pay lines in the direction of symbol movement because symbol arrangements in that direction are predetermined.
The foregoing will have made clear that the conventional belief that the rows of symbols must essentially revolve about a common axis has been a bar to a greater variety of random symbol combinations and, therefore, to the greater enjoyment of the player.